Advice on GTIL Inverter

SanDiegoMaxim

New member
Joined
Aug 18, 2019
Messages
6
Wolf said:
Solardad said:
Has anyone successfully setup the 2000w version in the US / split phase setup (120/240)?

Stumped in understanding if it is possible given the output is 220v. I assume wire output is euro spec., 1 hot, 1 neutral and 1 ground vs. US 2 hot and 1 neutral/ground.

I would love to have the larger inverter vs multiple 1ks at that price.

If so how did you wire it to your breaker?

Thanks...!

I assume you bought the US version which floats the groundas a neutral.

Wiring diagram is in this post.


Let me know if you have any questions


Wolf



Hi Wolf and all
I am inexperienced, but I really hope you can help me with my new project.

I have a workshop where I consume 1000W-1200W per hour from 8:00 to 17:00 (this is mainly my LED lighting). At night and on weekends it is about 0.1 kWh. Very important information that mainly in my workshop consumption goes on ONE phase the load 8 AM - 5 PM : L1 - 90% and L2 - 10% (on L1 - approx 9A)

I need your advice!
[size=small][size=small]
Question 1:[/size]
[/size]

which model GTIL2 to buy considering all the data on my consumption? 1000W or 2000W? Which will suits better?
[size=small][size=small][size=small]Question2:[/size][/size][/size]
Question about the CT sensor (s). If consumption is in one phase L1, then maybe I do not need separate split-phase sensors?

I have many used German panels 280 watts 5years old SOLARWORLD SW280 MONO BLACK Voc 39

[*]Nominal Maximum Power (Pmax): 280 Watts
[*]Open Circuit Voltage (Voc): 39.50 Volts
[*]Maximum Power Point Voltage (Vmpp): 31.20 Volts
[*]Short Circuit Current (Isc): 9.71 Amps
[*]Maximum Power Point Current (Impp): 9.07 Amps


Question3:
How many panels do I needto connect for 2000w model? 8 panels: 2s 4p?

Please tell me how should I build a system?
image_jlewpn.jpg

image_rcxbwc.jpg
 

Korishan

Moderator
Staff member
Joined
Jan 7, 2017
Messages
6,423
This is a question about "using" the GTIL, not external limiting.

If you don't like the title, please do a Full Edit on the original post and you can change the title.
 

ajw22

Well-known member
Joined
Nov 16, 2018
Messages
584
A few more infos needed for giving good advice:

Are you in the US with split L1: 120V, Neutral, L2:120V ? The 2000W model does only supports 190~260VAC.
Are you planning to add batteries? Without, you'll waste PV power you didn't use, especially wasteful over the weekends. With battery, that power could be stored for use in the evenings (tiny consumption, but it adds up!) and when cloudy/rainy.
 

Doin it

Member
Joined
Mar 17, 2019
Messages
331
For the 2000w U would want to use 6 of those panels 2 in series 3 in parallel. U could use 8 panels instead of 6 but that put your amps over max amps for your inverter even tho they say they limit the amperage on their own I wouldnt install panels that arent going to be maxing the amps the inverter can handle. Also the 2000w version is 240v so u would have to supply power to both legs of main panel. I think u should use 1000w version 45-90v which is better for your really unbalanced main panel loads, since u said most of your loads are on one leg. So then u would want 2 panels in series and 2 of those sets in parallel. If using the 1000w u need only 1 ct cuz u are only supplying to one leg of your main panel.
If u plan to use batteries full time the u can make your pv array whatever size a charge controller that u would use could handle
 

ajw22

Well-known member
Joined
Nov 16, 2018
Messages
584
It is sound advice to not run the inverters at 100%. But with these GTIL, you can limit the output to any value (either output Watts, or input Amps), so there is absolutely no problem attaching 3000W of PV panels to a 1000W GTIL. In fact, since PV panels rarely output 100% of rated power, it's not a bad advice to oversize the panels.
Just make sure to keep the OC voltage within the supported max.

For my system (with batteries), I currently have 2x 1kW GTIL units set to output max 750W each (just during the HOT summer), attached to 6.4kW of PV panels.
 

ajw22

Well-known member
Joined
Nov 16, 2018
Messages
584
Of course, the number of panels connected in series (Voc * series) must always be lower than what the maximum voltage the inverter is capable of.
But with _these_(*1) GTIL you can connect as many PV panels in parallel as you want (*2), because it will only take as much current as it is capable of (or is limited to).

So there is absolutely no problem connecting even 20 PV panels (=5600W) in 10p2s or 2s10p configuration to the GTIL1000.
If you think about it, how is the GTIL supposed to know if it's connected to 20 PV panels, or to a strong battery? The input ports are the same, and there is no setting to configure what type the power source is.


(*1) Many other inverters are not like this, and will get fried if you connect more kW of PV panels than the inverter is rated for!
(*2) Beware of fusing/breaker requirements when connecting many panels in parallel. Otherwise the cable might catch fire during malfunctions or accidental shorts.
 

SanDiegoMaxim

New member
Joined
Aug 18, 2019
Messages
6
ajw22 said:
A few more infos needed for giving good advice:

Are you in the US with split L1: 120V, Neutral, L2:120V ? The 2000W model does only supports 190~260VAC.
Are you planning to add batteries? Without, you'll waste PV power you didn't use, especially wasteful over the weekends. With battery, that power could be stored for use in the evenings (tiny consumption, but it adds up!) and when cloudy/rainy.

Thank you so much for your reply. Yes, I'm inSan Diego and it is still in the USA. :heart:
I read your answer andI'm confused now. I thought that there are European models 1 phase- 220-240 volts, and there are models for the USA where there are split phases. Where there are L1 and L2 two split phases.

image_rdaqul.jpg


If 2000W model does only supports 190~260VAC thenwhy do people in the United States buy 2000 models? if they use only190~260VAC.
I saw this picture about the 2000 model and it says that in this model there are two lines of 110

image_sfrkag.jpg



So please what is190~260VAC? :(
I apologize perhaps for a stupid question.

And I was interested in your comment about the batteries. What is the best way to connect them? Do you have a reliable connection scheme? So many different schemes, I just got confused.



Doinit said:
For the 2000w U would want to use 6 of those panels 2 in series 3 in parallel. U could use 8 panels instead of 6 but that put your amps over max amps for your inverter even tho they say they limit the amperage on their own I wouldnt install panels that arent going to be maxing the amps the inverter can handle. Also the 2000w version is 240v so u would have to supply power to both legs of main panel. I think u should use 1000w version 45-90v which is better for your really unbalanced main panel loads, since u said most of your loads are on one leg. So then u would want 2 panels in series and 2 of those sets in parallel. If using the 1000w u need only 1 ct cuz u are only supplying to one leg of your main panel.
If u plan to use batteries full time the u can make your pv array whatever size a charge controller that u would use could handle

I was interested in your comment about the batteries. What is the best way to connect them? Do you have a reliable connection plan? So many different schemes, I just got confused.
 

ajw22

Well-known member
Joined
Nov 16, 2018
Messages
584
There are other GTI with limiters, so just to make sure that we're talking about the same devices:
https://www.amazon.com/dp/B076KBCHBM/ref=cm_sw_em_r_mt_dp_U_OlKwDb4B6HZ3C

As far as I know, there are only 3 versions. The US/Australian/European/etc versions only differ in the included localized power plug. There is no real ("proper") split phase support with these devices.
1. GTIL1000 supporting both AC 90V~140V and 190VAC~260VAC (auto sensing), DC 25V~60V
2. GTIL1000 supporting both AC 90V~140V and 190VAC~260VAC (auto sensing), DC 45V~90V
3. GTIL2000 supporting just AC 190V~260V, DC 45V~90V

There are 3 ways to connect them to the US split phase system:
1. Use one GTIL1000 device on L1-N (120V), sensor clamp on L1. Optionally use 2nd GTIL1000 device on L2-N (120V), sensor clamp on L2. This is the safest bet as it will work with no backfeeding on the(/either) phase. So the utilities company will be none the wiser.
2. Use a GTIL1000 device on L1-N (120V), modified dual sensor clamp on L1 and L2. There will be backfeeding on one phase, but will be offset by draw on the other phase. Might be a problem with some meters / utility companies. Modification of sensor clamp is simple and proven.
3. Use a GTILx000 device on L1-L2 (240V), modified dual sensor clamp on L1 and L2. There will be backfeeding on one phase, but will (really?) be offset by draw on the other phase. Might be a problem with some meters / utility companies. Modification of sensor clamp is... let's just say there are looong active threads about it.

The resellers claiming split phase support are referring to methods #2 and #3. Misleading at the least.

If one GTIL is not enough, you can install 2 or more devices on the same phase. But they will not share the workload equally.


Batteries: Have a look at my project page for a working example. Quite happy with all the components, but gathering battery cells is quite a lot of work. Of course you can save yourself a lot of work by using Nissan Leaf, Volt, or Tesla batteries.
In any case, you better plan it beforehand, because charge controllers and GTIL may have different voltage requirements. Rewiring your PV panels afterwards to increase/decrease voltage would be a PITA.
 

Wolf

Well-known member
Joined
Sep 25, 2018
Messages
1,427
ajw22 said:
There are other GTI with limiters, so just to make sure that we're talking about the same devices:
https://www.amazon.com/dp/B076KBCHBM/ref=cm_sw_em_r_mt_dp_U_OlKwDb4B6HZ3C
......................................................
ajw22,
Very well explained!
If we are talking about the GTIL2. as you have linked above.
I run 2 of them each on their own 120v leg and working just great!!.

Sandiegomaxim,
The theoretical max wattage you should be able to get out of a single GTIL2 is 1000W but that as far as I can determine is more like a max of 850W to 900W.
Now that being said I do run my system off of a 48v nominal battery bank and I have heard that if you do that the wattage is throttled a bit. The drawing you saw originally was me hooking up a single GTIL2 1000 to my 240 split phase panel. My L1 and L2 feeds where not very well balanced (30%/70%) so I was always slightly backfeeding the grid. You can find that discussion with graphs and charts in thehttps://secondlifestorage.com/t-External-limiting-an-GTIL2-SUN-1000G2-with-raspberry?pid=51964#pid51964 thread.

Now in your original post you stated that 1 leg uses 1000W to 1200W consistently throughout the working day.
In your case I would hook a GTIL2 1000 to that 1 leg and depending on your Panel production you will probably shave 800W to 950W off of your grid consumption.
In my case I bought another GTIL2 1000 moved 1 circuit breaker and balanced my loads between L1 and L2 to a much better level.
so I have 1 GTIL feeding L1 and 1 GTIL feeding L2 .
Are you sure you cannot move 1 or 2 circuit breakers to balance your load? Then you could have 2 GTIL 1000 and basically run the shop during the day without much grid interaction. Well as long as the sun is out and in San Diego I would imagine that that is most of the time.

Here is my solar production yesterday it was a pretty cloudy day most of the day and the AC was on as it was warm and humid.
Nice stretch from about 9AM to 5:30PM without much grid usage.

image_bhqxyo.jpg


On a separate note I don't want to step on anyone's toes but I would not use the GTIL 2000 as it is 240V onlyand in your case would cause a serious backfeed problem. Especially if you did not change your L1 and L2 imbalance.
Wolf
 

Doin it

Member
Joined
Mar 17, 2019
Messages
331
Agreed with wolf, do not use 240v version if legs are badly unbalanced in main panel


Ajw22 read my last comment on external limiting. It explains what actually happens at 240v using the gtil2 and dual clamps


It does not backfeed on 1 leg and underfeed other...it actually sees it would backfeed and just throttles down to not do so..but then not fully supplying one leg therefor letting the grid supply the unfed power...read my last text in blue on the external limiting post, I was talking to someone on messenger when I figured this out so I just took a pic and put it on here


Using a 120v inverter on each leg and batteries avoids all that but there is losses using batteries and batteries last maybe 10yrs so a lot of added cost to bottom line, some saving only 40 a month like some ppl do when having 2 120v inverters itd take a long time to get your investment back to actually start saving.where as I have 2 240v inverters supplying both legs with 4kw pv (2 2kw arrays) that cost me 4K total for the entire setup and will recoup that cost in less than 4 yrs. If batteries arent used and 120v inverter wired to one leg then panels connected to that inverter cant help other leg so loses there aswell


So if it is understood that the 240v inverter does not backfeed but rather throttles down to not backfeed on the one leg therefor underfeeding the other leg,,,the amount underfed is what the inverters show being supplied by grid when inverters are supplying all of loads but letting grid supply aswell. Which isnt many watts as long as main panel is fairly balanced. Single phase gtil can backfeed with limiter installed if main panels legs loads are more than 30% different. The amount the grid is supplying (over time) can be chalked up to the cost of a setup that had batteries. But not having to have to deal with batteries,,balancing (more so with lithium) gassing (more so with lead acid) maintenance and having to replace in 10 yrs if they make it that long....
Edison batteries are better cuz they last forever and balancing isnt an issue but a lot of upfront cost..
On the other hand if someone wants offgrid capabilities they need batteries regardless
 

Wolf

Well-known member
Joined
Sep 25, 2018
Messages
1,427
Doinit said:
Using a 120v inverter on each leg and batteries avoids all that but there is losses using batteries and batteries last max of 10yrs so a lot of added cost to bottom line, some saving only 40 a month like some ppl do when having 2 120v inverters itd take a long time to get your investment back to actually start saving.where as I have 2 240v inverters supplying both legs with 4kw pv (2 2kw arrays) that cost me 4K total and will recoup that cost in less than 4 yrs. If batteries arent used and 120v inverter wired to one leg then panels connected to that inverter cant help other leg so loses there aswell

All very true, here comes the but.

But, a lot of us here are into reusing a product that gets thrown out and we try to recycle.
Partially because we are environmentally conscious and we are Amateur("Amateur" definition, a person who engages in a study, sport, or other activity for pleasure rather than for financial benefit or professional reasons)tinkerersthat need something to do with our spare time and keep our brains sharp. Will I ever recoup my investment probably not. But the money I used to spend on alcohol was wasted also as it was flushed into the sewer system after consuming it. There was no return on investment whatsoever other than a bad headache. :s

The batteries in my case are of a twofold use. They buffer my solar production for my GTIL but also are a standby for my full fledged split phase inverter in case the power goes out. With my battery bankI have at least 5 hrs of emergency power till I have to fire up my gas generator.
With my 18650 Li-Ion battery bank I want to increase that to at least 24 hrs if not 48 hrs.
So all in all yea I have a lot of money invested but that is not the criteria most of us,at least I believe, most of us are here for.

I think most of us are here to construct something that we can be proud of, is a useful project for the environment andwhen the neighbors come over and see what we have done they just uhh and ahh. Wow that is awesome etc.

Wolf
 

Doin it

Member
Joined
Mar 17, 2019
Messages
331
Lol wolf yeah I guess so...I just added in above comment that ppl need batteries if they want offgriid...for me tho its all about making that electric bill low as possible for as little money as possible and getting the cost of the system recouped quick as possible...I do like the ohhhs and ahhhs aswell tho.
Also there seems to be new battery technology coming to light in the near future..liquid metal batteries have made advancements and a few others
 

Wolf

Well-known member
Joined
Sep 25, 2018
Messages
1,427
I am all for safety but that is a little over the top I think.

I have 1 breaker on the DC side 50 Amp and I have 2breaker on the AC side 20 Amp X2. 1 each for L1 and L2
As I am using 2 GTIL and I have them hooked to my battery that get charged from my solar I have them throttled to 950 Watts each.
They both rarely go that high (1900 Watts ~40 Amps depending on voltage) and if, for a very short time.
The on and off timer eh it's not a bad idea but then again running on batteries I don't know when the cutoff voltage to put the GTIL to sleep will happen. Also I don't know what kind of weather cloudy, full sun , partly cloudy etc I will have during the day. The GTIL does a great job in regulating itself using the resources it has to produce as much power asit can.
All this is programmable on the GTIL.
I have the go to sleep voltage set to 49.5 volts and the wakeup (reboot) voltage at 54 volts.
Essentially what happens is the batteries will get charged in the AM and when they hit 54 volts the GTIL will wake up and start to produce power.
Actually they start at ~53.5 volts just to wake up and go full bore at 54 volts
The GTIL will use whatever is necessary to feed the house and theexcess from the panels will continue to charge the batteries.
When the sun starts to go away the battery will supply the GTIL till the battery voltage gets to ~50 volts and throttle themselves down slowly till 49.5V at which point they go to sleep drawing ~170mA from my battery.
I don't like to shock electronic systems with full on and full off scenarios. I know for a fact that when you hook the GTIL to a battery there is a quick inrush of power to charge the primary capacitors and it is quite a spark. That wouldn't happen with a solar array per say if you turn it on in the early AM but turn that breaker on midday there will be some arcking especially the DC side.

So safety yes but there can be overkill.
Surge protection sure but we don't live in the Philippines and certainly don't generally have daily thunderstorms and an unpredictable grid.

Just my view IMHO

Wolf
 

Wolf

Well-known member
Joined
Sep 25, 2018
Messages
1,427
SanDiegoMaxim said:
Wolf said:
I am all for safety but that is a little over the top I think.

Please look at this diagram, did I set everything correctly or am I mistaken?

If you are going to go with all that then yes it looks OK as long as the "red" wire is hooked to a breaker that is supplied by the leg you are monitoring with the CT from the GTIL.


Disclaimer
I am not a licensed electrician I just play one on TV.

Wolf
 

Doin it

Member
Joined
Mar 17, 2019
Messages
331
Hey wolf, what would u recommend to monitor my home usage and solar production..I seen u use iotawatt... would u still recommend that..Im not very tech savvy. Id like something easy that I could monitor on my iPad. The iotawatt seems to plug into a 120 outlet but I see other devices that actually get wired to a 240v breaker as to see individual voltage difference between the phases.
 

SanDiegoMaxim

New member
Joined
Aug 18, 2019
Messages
6
Wolf said:

I saw, that some installed 4 GTIL2 in one house. is it possible to put several GTIL2 on one phase L1?
Is it possible to install 2 or 3 invertors without a limiter to grid?
 
Top